Abrasion alert sleeves and sleeve assemblies, and methods of using same

ABSTRACT

Abrasion alert sleeves and sleeve assemblies, and methods of using them, are disclosed. The abrasion alert sleeves include protective threads and indicator or warning threads. The protective threads are placed so as to substantially shield or hide the indicator threads unless and until the protective threads become abraded, at which time, the indicator threads become more visible. The abrasion alert sleeves and sleeve assemblies thus provide protection for hydraulic or pneumatic lines, while enabling relatively easy detection of abrasion alert sleeves or sleeve assemblies that need to be replaced due to wear. Various methods for implementing inventory control procedures and replacement procedures are also disclosed.

BACKGROUND OF THE INVENTION

a. Field of the Invention

The present invention is directed toward abrasion resistant sleeves andsleeve assemblies, and toward methods of using them, for a variety ofapplications including the protection of hydraulic or pneumatic lines,electric wiring, or other critical components exposed to abrasion. Morespecifically, it relates to single-walled abrasion alert sleeves thatmay be used individually or embedded one inside another, wherein atleast one sleeve is woven from different colored yarns or threads,including protective yarns or threads of a first, base color andindicator yarns or threads of a second, contrasting color.

b. Background Art

It is well known that hydraulic and pneumatic lines on pieces of heavyequipment and other machinery move or shift during operation. Forexample, as hydraulic or pneumatic lines are pressurized anddepressurized, they may move laterally or longitudinally, and they mayexpand or swell and contract or shrink. As the lines move, they may bumpagainst, rub against, or abrade adjacent lines or adjacent portions ofthe equipment or machinery. The bumping, rubbing, or abrading contactbetween the lines and each other, or the lines and portions of theequipment or machinery, can unduly shorten the life of the lines. Sinceworn-out hydraulic lines lead to equipment downtime, which itself may becostly to the equipment owner, and since the hydraulic lines themselvesmay be expensive to replace, people have sought ways to increase thelife of hydraulic lines using various techniques, including more carefulplacement or routing of the hydraulic lines and various techniques forprotecting or shielding the hydraulic lines themselves.

One of these existing techniques for extending the life of hydrauliclines is to place a protective sleeve around the hydraulic linesthemselves for abrasion resistance. These prior art tubular webbingstructures, which slide over hydraulic lines, have been constructed fromindustrial fabrics having threads or yarns of a single color. Althoughsuch sleeves are able to protect the hydraulic lines, additional timeand effort is required to closely monitor these single-color sleeves forexcessive wear so that the sleeves may be replaced before they cease toperform their protective function.

Multi-walled devices also exist that could be used to protect hydrauliclines. In these latter devices, each single-walled sleeve forming themulti-walled device is constructed from a single color of thread. Amulti-walled device may be constructed from one single-walled sleevemade entirely from a first color of thread, and a second single-walledsleeve made entirely from a second color of thread that is differentfrom the first color. Multi-walled sleeves are, however, relativelyexpensive to make and install. The sleeves that are used to protect thehydraulic lines should be less expensive than the hydraulic linesthemselves, and they should be easy to install.

Thus, there remains a need for a protective device to safeguardhydraulic lines on heavy equipment or other machinery that is relativelyinexpensive to manufacture and that facilitates easy monitoring of wearon the protective device itself.

BRIEF SUMMARY OF THE INVENTION

It is desirable to be able to protect hydraulic lines (and othercomponents that may be subject to abrasion like pneumatic lines, andelectrical leads) with a protection device that not only protects thehydraulic lines, but also readily alerts those who use or maintain theequipment or machinery when the protection device is in need of repairor replacement. Accordingly, it is an object of the disclosed inventionto provide an improved abrasion protection device.

The invention comprises a single-walled abrasion alert sleeve whereinthe wall is woven from threads or yarns of different colors. Forexample, an abrasion alert sleeve according to the instant invention mayinclude protective threads or yarns of a base color (e.g., black)interwoven with indicator or warning threads or yarns of a contrastingcolor (e.g., red or yellow). The protective threads substantially shieldor hide the indicator threads when the abrasion alert sleeve is new. Asthe abrasion alert sleeve protects the hydraulic lines, the protectivethreads are worn away, and more and more indicator threads becomevisible over time. In other words, when the protective threads becomeworn or abraded, the indicator threads of a contrasting color arerevealed. The indicator threads thus visually indicate in a relativelyeasily observable way when the abrasion alert sleeve may fail to protectthe hydraulic line and needs to be removed from service. In addition tostandalone sleeves, the present invention also comprise abrasion alertsleeve assemblies comprising at least one of these single-walledstandalone abrasion alert sleeves used in combination with one or moreadditional sleeves.

In one form, the present invention comprises an abrasion resistantdevice for the protection of a component that would otherwise be exposedto direct abrasion. In this form, the device comprises a single-walled,tubular abrasion alert sleeve woven from longitudinally-extending,protective yarns of a base color interwoven with laterally-extending,indicator yarns of a contrasting color, wherein the base color isdifferent from the contrasting color, and wherein the protective yarnssubstantially conceal the indicator yarns from view.

In another form, the present invention is an abrasion alert jacketcomprising a single-walled, tubular structure having a longitudinal axisand constructed from threads having at least two contrasting colors tofacilitate use of the abrasion alert jacket as a wear indicator. Thesethreads include a first plurality of longitudinally-extending protectivethreads, the protective threads being of a dominant color and beingarranged substantially parallel to the jacket longitudinal axis. Thethreads also include a second plurality of indicator threads extendingsubstantially perpendicularly to the first plurality oflongitudinally-extending protective threads, the indicator threads beingof an indicator color and being interwoven with the first plurality oflongitudinally-extending protective threads so as to be substantiallyshielded by and hidden among the first plurality oflongitudinally-extending protective threads when the abrasion alertjacket is unworn. The indicator threads are adapted to become visible asthe protective threads become worn.

In yet another form, the present invention comprises a multi-tube,sleeve assembly of concentrically-embedded sleeves for the protection ofa critical component that would otherwise be directly exposed toabrasion. In this form, the sleeve assembly comprising an outermost,single-walled sleeve circumscribing a first interior region, theoutermost sleeve being constructed from protective threads of a basecolor and indicator threads of a first contrasting color. The sleeveassembly also comprises an innermost, single-walled sleevecircumscribing a second interior region, the innermost sleeve beinglocated inside the first interior region, and the innermost sleeve beingconstructed from protective threads of the base color and indicatorthreads of a second contrasting color, wherein the first contrastingcolor is different from the second contrasting color, and wherein thecritical component resides within the second interior region.

In still another form, the present invention comprises an abrasion alertsleeve assembly having a-tube-inside-a-tube construction. In this form,the sleeve assembly comprises a first, single-walled, abrasion alertsleeve having a first longitudinal axis and constructed from threads ofat least two contrasting colors to facilitate use of the first abrasionalert sleeve as a first wear indicator. The threads of the firstabrasion alert sleeve include a first plurality oflongitudinally-extending protective threads, the first plurality ofprotective threads being of a first base color and being arrangedsubstantially parallel to the first longitudinal axis; and a secondplurality of indicator threads extending substantially perpendicularlyto the first plurality of protective threads, the second plurality ofindicator threads being of a first indicator color and being interwovenwith the first plurality of protective threads so as to be substantiallyshielded by and hidden among the first plurality of protective threadswhen the first abrasion alert sleeve is unworn, and wherein the secondplurality of indicator threads are adapted to become more clearlyvisible as the first plurality of protective threads become worn. Inthis form, the sleeve assembly further comprises a second,single-walled, abrasion alert sleeve having a second longitudinal axisand constructed from threads having at least two contrasting colors tofacilitate use of the second abrasion alert sleeve as a second wearindicator, wherein the second abrasion alert sleeve is embedded withinthe first abrasion alert sleeve. The threads of the second abrasionalert sleeve include a third plurality of longitudinally-extendingprotective threads, the third plurality of protective threads being of asecond base color and being arranged substantially parallel to thesecond longitudinal axis; and a fourth plurality of indicator threadsextending substantially perpendicularly to the third plurality ofprotective threads, the fourth plurality of indicator threads being of asecond indicator color and being interwoven with the third plurality ofprotective threads so as to be substantially shielded by and hiddenamong the third plurality of protective threads when the second abrasionalert sleeve is unworn, and wherein the fourth plurality of indicatorthreads are adapted to become more clearly visible as the thirdplurality of protective threads become worn. The first base color may bethe same as the second base color.

In another form, the present invention comprises a multi-walled,abrasion resistant sleeve assembly constructed from a plurality ofembedded, single-walled, abrasion alert sleeves including an outermost,single-walled sleeve woven from threads of at least two contrastingcolors; and an innermost, single-walled sleeve woven from threads of asingle color. This form of the present invention may further comprise atleast one intermediate sleeve woven from threads of at least twocontrasting colors and inserted between the outermost sleeve and theinnermost sleeve. The thicknesses of the sleeves may vary in any desiredway, or the sleeves may all have the same thickness.

The present invention also comprises a method of protecting a criticalcomponent in an abusive environment using single-walled, multi-colored,abrasion alert sleeves. In this form, the method comprises the steps of(a) installing a first abrasion alert sleeve over the criticalcomponent, the first abrasion alert sleeve comprising a first pluralityof protective threads of a first base color and a first plurality ofindicator threads of a first warning color, wherein the first pluralityof protective threads are woven with the first plurality of indicatorthreads so as to substantially hide the first plurality of indicatorthreads; (b) monitoring the first abrasion alert sleeve for theappearance of the first warning color; and (c) removing the firstabrasion alert sleeve and installing a replacement abrasion alert sleeveupon the appearance of a substantial amount of the first warning color.The first base color may be, for example, black, and the first warningcolor may be, for example, yellow or red.

In yet another form, the present invention comprises a method ofprotecting a critical component in an abusive environment using anabrasion alert sleeve assembly comprising a plurality of abrasion alertsleeves. This method comprises the steps of (a) installing a firstabrasion alert sleeve assembly over the critical component, the firstabrasion alert sleeve assembly comprising (1) an outermost,single-walled abrasion alert sleeve, the outermost abrasion alert sleevecomprising a first plurality of protective threads of a first base colorand a second plurality of indicator threads of a warning color, whereinthe first plurality of protective threads are woven with the secondplurality of indicator threads so as to substantially hide the warningcolor; and (2) an innermost, single-walled abrasion alert sleeve, theinnermost abrasion alert sleeve comprising a third plurality of threadsof a second base color; (b) monitoring the first abrasion alert sleeveassembly for the appearance of the warning color; and (c) removing andreplacing the outermost abrasion alert sleeve upon the appearance of asubstantial amount of the warning color.

In still another form, the present invention comprises a method ofprotecting a critical component in an abusive environment using anabrasion alert sleeve assembly comprising a plurality of multi-colored,abrasion alert sleeves. This method comprising the steps of (a)installing a first abrasion alert sleeve assembly over the criticalcomponent, the first abrasion alert sleeve assembly comprising (1) anoutermost, single-walled abrasion alert sleeve, the outermost abrasionalert sleeve comprising a first plurality of protective threads of afirst base color and a first plurality of indicator threads of a firstwarning color, wherein the first plurality of protective threads arewoven with the first plurality of indicator threads so as tosubstantially hide the first plurality of indicator threads; and (2) aninnermost, single-walled abrasion alert sleeve, the innermost abrasionalert sleeve comprising a second plurality of protective threads of asecond base color and a second plurality of indicator threads of asecond warning color, wherein the second plurality of protective threadsare woven with the second plurality of indicator threads so as tosubstantially hide the second plurality of indicator threads; (b)monitoring the first abrasion alert sleeve assembly for the appearanceof the first warning color; (c) ordering a replacement sleeve assemblyupon the appearance of a substantial amount of the first warning color;(d) monitoring the first abrasion alert sleeve assembly for theappearance of the second warning color; and (e) removing the firstsleeve assembly and installing the replacement sleeve assembly upon theappearance of a substantial amount of the second warning color.

In another form, the present invention comprises a method of controllinginventory of abrasion resistant sleeve assemblies and ensuring timelyreplacement of worn abrasion resistant sleeve assemblies. This methodcomprising the steps of (a) installing an abrasion resistant sleeveassembly, the abrasion resistant sleeve assembly comprising embeddedabrasion alert sleeves, including (1) an outermost, order-now, abrasionalert sleeve, the outermost abrasion alert sleeve comprising a firstplurality of protective threads of a first base color and a firstplurality of indicator threads of a first warning color, wherein thefirst plurality of protective threads are woven with the first pluralityof indicator threads so as to substantially hide the first plurality ofindicator threads; (2) an innermost, replace-now, abrasion alert sleeve,the innermost abrasion alert sleeve comprising a second plurality ofprotective threads of a second base color and a second plurality ofindicator threads of a second warning color, wherein the secondplurality of protective threads are woven with the second plurality ofindicator threads so as to substantially hide the second plurality ofindicator threads; (b) monitoring the abrasion resistant sleeve assemblyduring use for evidence of wear manifested as abraded and brokenprotective threads thereby revealing the warning threads; (c) ordering anew abrasion resistant sleeve assembly upon the appearance of the firstwarning color; and (d) replacing the abrasion resistant sleeve assemblyupon the appearance of the second warning color. The thickness of theabrasion alert sleeves comprising the abrasion resistant sleeve assemblymay be adjusted to thereby adjust the protection afforded by theabrasion resistant sleeve assembly.

In yet another form, the present invention comprises a method ofestablishing service intervals for abrasion alert sleeve assemblies thatare being used to protect a critical component. This method comprisingthe steps of (a) installing a first abrasion alert sleeve assembly overthe critical component, the first abrasion alert sleeve assemblycomprising a plurality of single-walled abrasion alert sleeves ofapproximately the same thickness, including (1) an outermost,single-walled abrasion alert sleeve, the outermost abrasion alert sleevecomprising a first plurality of protective threads of a first base colorand a first plurality of indicator threads of a first warning color,wherein the first plurality of protective threads are woven with thefirst plurality of indicator threads so as to substantially hide thefirst plurality of indicator threads; (2) a first intermediate,single-walled abrasion alert sleeve, the first intermediate abrasionalert sleeve comprising a second plurality of protective threads of asecond base color and a second plurality of indicator threads of asecond warning color, wherein the second plurality of protective threadsare woven with the second plurality of indicator threads so as tosubstantially hide the second plurality of indicator threads; (3) asecond intermediate, single-walled abrasion alert sleeve, the secondintermediate abrasion alert sleeve comprising a third plurality ofprotective threads of a third base color and a third plurality ofindicator threads of a third warning color, wherein the third pluralityof protective threads are woven with the third plurality of indicatorthreads so as to substantially hide the third plurality of indicatorthreads; and (4) an innermost, single-walled abrasion alert sleeve, theinnermost abrasion alert sleeve comprising a fourth plurality ofprotective threads of a fourth base color and a fourth plurality ofindicator threads of a fourth warning color, wherein the fourthplurality of protective threads are woven with the fourth plurality ofindicator threads so as to substantially hide the fourth plurality ofindicator threads; (b) assessing a wear state of the first abrasionalert sleeve assembly by monitoring the first abrasion alert sleeveassembly for the appearance of at least one of the first warning color,the second warning color, the third warning color, and the fourthwarning color; (c) estimating a life expectancy for the first abrasionalert sleeve assembly by monitoring how long it takes for the firstwarning color to initially appear; (d) adjusting the estimated lifeexpectancy based upon how long it takes for the second and third warningcolors to initially appear; (e) ordering a replacement sleeve assemblybased upon the estimated life expectancy; and (f) installing thereplacement sleeve assembly upon the initial appearance of the fourthwarning color.

The protection afforded by an abrasion alert sleeve assembly accordingto the present invention may be adjusted or controlled by increasing ordecreasing the number of embedded sleeves comprising the abrasion alertsleeve assembly. The protection afforded by the abrasion alert sleeveassembly may also be adjusted or controlled by changing the thickness ofthe abrasion alert sleeves comprising the abrasion alert sleeve assemblyrelative to each other.

The foregoing and other aspects, features, details, utilities, andadvantages of the present invention will be apparent from reading thefollowing description and claims, and from reviewing the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric, fragmentary view of an abrasion alert sleeveaccording to a first embodiment of the present invention.

FIG. 2 is an enlarged, fragmentary view of the indicated region of FIG.1 depicting further details of the woven material comprising theabrasion alert sleeve according to the first embodiment.

FIG. 3 is a further-enlarged, fragmentary, cross-sectional view of thematerial depicted in FIGS. 1 and 2 taken along line 3-3 of FIG. 2.

FIG. 4 is a fragmentary view of the abrasion alert sleeve materialdepicted in FIGS. 1-3, wherein some of the protective threads or yarnshave been abraded or broken thereby revealing more of the indicatorthreads or yarns.

FIG. 5 depicts a second embodiment of the present invention, comprisingan abrasion alert sleeve assembly formed from four embedded abrasionalert sleeves of similar thickness.

FIG. 6 depicts a third embodiment of the present invention, comprisingan abrasion alert sleeve assembly formed from three embedded abrasionalert sleeves, wherein each sleeve has a somewhat different thicknessfrom each of the other sleeves.

FIG. 7 is a fragmentary, isometric view of a piece of heavy equipmenthaving hydraulic lines that are protected by abrasion alert sleevesaccording to the present invention.

FIG. 8 is an enlarged, fragmentary view of the circled portion of FIG. 7and depicts a first hydraulic line moving or shifting under theinfluence of pressure fluctuations relative to a second hydraulic line.

FIG. 9 is a fragmentary view of a first hydraulic line moving under theinfluence of pressure fluctuations laterally into and out of bumpingcontact with a second hydraulic line.

FIG. 10 is a fragmentary, isometric view depicting abrasion resultingfrom rubbing contact between two adjacent hydraulic lines.

DETAILED DESCRIPTION OF THE INVENTION

A number of embodiments of single-walled, abrasion alert sleeves orjackets 10 (see, e.g., FIGS. 1-4) and abrasion alert assemblies 12, 14(see, e.g., FIGS. 5 and 6) comprising a plurality of single-walledabrasion alert sleeves or jackets are disclosed. An advantage of theinstant invention over the prior art is that each single-walled abrasionalert sleeve 10, whether used alone or in combination with othersingle-walled, abrasion alert sleeves, is constructed from threadshaving at least two different colors, which facilitates use of theabrasion alert sleeves as wear indicators. Thus, using the abrasionalert sleeves according to the present invention, it is possible toprotect hydraulic or pneumatic lines while controlling inventory andensuring timely replacement of worn sleeves.

Referring first to FIGS. 1-4, an abrasion alert sleeve 10 according to afirst embodiment of the present invention is described. FIG. 1 is afragmentary, isometric view of a section of an abrasion alert sleeve orjacket 10. The abrasion alert sleeve depicted in FIG. 1 compriseslongitudinally-extending protective threads 16 that are parallel to asleeve longitudinal axis 18. Indicator threads 20, which are moreclearly visible in FIGS. 2-4, are also present and extend substantiallylaterally of (i.e., substantially perpendicular to) the protectivethreads 16. The orientation and placement of the protective threads oryarns 16 relative to the indicator threads or yarns 20 may be moreeasily seen in FIGS. 2-4. In FIG. 2, which is an enlarged view of theportion of the abrasion alert sleeve 10 circled in FIG. 1, the relativeposition of the protective threads 16 and the indicator threads 20 maybe more clearly seen. In particular, the protective threads, which areof a “base” or “dominant” color (e.g., black), substantially shield theinterwoven indicator threads, which are of an “indicating” or “warning”color (e.g., yellow or red). The base color contrasts with theindicating color. The “base” or “dominant” color is the color that ismost visible of the two contrasting colors in a new abrasion alertsleeve. In particular, the abrasion alert sleeve 10, when new, appearsto be of the base color since the indicator threads 20 are not easilyseen until the protective threads 16 become worn.

FIG. 3 is a further-enlarged, fragmentary, cross-sectional view of thematerial depicted in FIGS. 1 and 2 taken along line 3-3 of FIG. 2. FIGS.2 and 3 clearly show how the weave pattern is established to hide theindicator threads 20 among the protective threads 16. Although theindicator threads are slightly visible in a new abrasion alert sleeve,their visibility is hampered by the relative position of the indicatorthreads 20 relative to the protective threads 16. As shown in FIG. 3,the indicator threads are embedded among and shielded by the protectivethreads, which are woven around the indicator threads. In thisconfiguration, the protective threads protect and substantially hide theindicator threads. Thus, when looking at a new abrasion alert sleeve 10like the one depicted in FIG. 1, the observer sees predominately theprotective threads 16 having the base color, and the indicator threads20 having the contrasting color are only partially visible. Since theprotective threads shield the indicator threads as the abrasion alertsleeve comes into contact with an abrasive surface, the protectivethreads 16 absorb the brunt of the impact and wear.

FIG. 4 is a fragmentary view of the abrasion alert sleeve materialdepicted in FIGS. 1-3, wherein some of the protective threads 22 havebeen abraded or broken thereby revealing more of the indicator threads.Thus, as the hydraulic lines are used, the protective threads 16 of theabrasion alert sleeve ultimately become abraded, damaged, or brokenthreads 22. As more and more of the protective threads thus fail or wearout, the previously hidden indicator threads are revealed. As depictedin FIG. 4, a number of protective threads have been worn through,thereby revealing relatively larger portions of the indicator threadsthan are visible in a new abrasion alert sleeve 10. Since the indicatorthreads 20 are of a contrasting color relative to the protective threads16, as more and more of the indicator threads are revealed, it becomesreadily apparent to an observer (e.g., someone who maintains theequipment) that the abrasion alert sleeve 10 has started to fail. Asdiscussed further below, replacement abrasion alert sleeves may beordered and installed based upon timing suggested by how predominant orvisible indicator threads have become as the protective threads wear orabrade.

When using a single-walled abrasion alert sleeve 10 woven from differentcolored threads, such as the sleeves or jackets just described inconnection with FIGS. 1-4, the sleeves may be more quickly manufacturedand may be manufactured at less cost than a multi-walled sleeve. If,however, it remains desirable to have a multi-walled sleeve, such asleeve may be constructed from a plurality of single-walled abrasionalert sleeves 10 wherein each single-walled sleeve is woven fromdifferent colored threads, and/or wherein single-walled sleeves wovenfrom different colored threads are interspersed with single-walledsleeves woven from a single color. FIG. 5 depicts a second embodiment ofthe present invention, comprising such an abrasion alert sleeve assembly12.

The abrasion alert sleeve assembly 12 depicted in FIG. 5 comprises fourembedded abrasion alert sleeves, including an innermost sleeve 24, anoutermost sleeve 26, a first intermediate sleeve 28, and a secondintermediate sleeve 30. In the embodiment of the abrasion alert sleeveassembly 12 depicted in FIG. 5, each of the sleeves 24, 26, 28, 30 isapproximately the same thickness as each of the other sleeves. A “pullthread” 32 or “leader yarn” is also visible in FIG. 5. Since it may bedifficult to insert a hydraulic or pneumatic line through the innermostsleeve 24 of the abrasion alert sleeve assembly 12, the pull thread 32may be placed in the innermost abrasion alert sleeve 24 duringproduction of the abrasion alert sleeve assembly 12. This pull thread 32may be tied or otherwise affixed to the hydraulic or pneumatic hose tobe protected to facilitate pulling the hose through the abrasion alertsleeve assembly 12. Clearly, the abrasion alert sleeve assembly maycomprise more or fewer abrasion alert sleeves than the four sleeves thatare depicted in FIG. 5.

FIG. 6 depicts a third embodiment of the present invention, comprisingan abrasion alert sleeve assembly 14 constructed from three abrasionalert sleeves. In this embodiment, the abrasion alert sleeves comprisingthe abrasion alert sleeve assembly 14 each has a somewhat differentthickness compared to each of the other sleeves. In FIG. 6, theoutermost sleeve 34 is the thinnest abrasion alert sleeve, the innermostsleeve 36 is somewhat thicker than the outermost sleeve, and the singleintermediate sleeve 38 is the thickest of the three abrasion alertsleeves comprising the depicted abrasion alert sleeve assembly 14.Clearly, the abrasion alert sleeve assembly may be constructed from moreor fewer abrasion alert sleeves, and the thickness of each abrasionalert sleeve may be different from what is depicted in FIG. 6. Forexample, the thickest abrasion alert sleeve of the sleeves comprisingthe abrasion alert sleeve assembly need not be the intermediate sleeve,and the thinnest abrasion alert sleeve need not be the outermost sleeve.

Through use of the abrasion alert sleeve assemblies 12, 14 depicted inFIGS. 5 and 6, a variety of different advantages may be obtained. Theseabrasion alert sleeve assemblies comprise multi-tube assemblies orconcentric-tube assemblies with at least one tube or sleeve inside ofanother tube or sleeve. The outermost sleeve may be constructed from,for example, protective threads of a base color and indicator threads ofa first contrasting color. The intermediate sleeve may be constructedfrom protective threads of the base color and indicator threads of asecond contrasting color. In such a sample abrasion alert sleeveassembly comprising two embedded abrasion alert sleeves, including anoutermost sleeve and an innermost sleeve, the appearance of theindicator threads of the first contrasting color may serve as noticethat it is time to order a replacement abrasion alert sleeve assembly,but not yet time to replace the abrasion alert sleeve assembly that hasbegun to wear. Appearance of indicator threads of the second contrastingcolor (i.e., appearance of the indicator threads comprising part of theinnermost abrasion alert sleeve) may serve as an indicator that it istime to replace the now more substantially worn abrasion alert sleeveassembly.

With the particular tube-inside-a-tube abrasion alert sleeve assemblydescribed in the last paragraph, the user receives multiple benefits. Inparticular, as the outermost sleeve begins to wear, thereby revealingthe indicator threads of the first contrasting color, the user may thenplace an order for a replacement abrasion alert sleeve assembly.Subsequently, when the indicator threads of the second contrastingcolor, which comprise part of the innermost abrasion alert sleeve, beginto be revealed in substantial quantities, the user may initiatereplacement of the entire abrasion alert sleeve assembly. In thealternative, when the indicator threads of the outermost sleeve begin tobe revealed as the protective threads of the outermost abrasion alertsleeve wear, the user may, at that time, replace the outermost abrasionalert sleeve before the innermost abrasion alert sleeve begins to wear.In this latter scenario, the innermost sleeve provides a “backup” or“safety” abrasion alert sleeve that preferably remains unabraded sincethe outermost sleeve is replaced as soon as it shows significant wearand before the innermost sleeve begins to wear or abrade. In thisscenario, since the outermost abrasion alert sleeve is replaced when itsindicator threads are sufficiently revealed, and the innermost sleeve ismerely a backup protector of the hydraulic or pneumatic lines, theinnermost sleeve may even comprise a less expensive sleeve comprised ofthreads of a single color. Alternatively, protective sleeves constructedfrom threads of a single color may be interspersed among or betweenabrasion alert sleeves having indicator threads with contrasting colorswoven among protective threads of the base color. Each sleeve of anabrasion alert sleeve assembly may be tacked to one or more adjacentsleeves or left free to move relative to any adjacent sleeve or sleeves.

As shown in FIG. 6, the ability to adjust the thickness of each sleeve34, 36, 38 (e.g., by weaving more threads together or by using thickerthreads), provides another option for protecting hydraulic or pneumaticlines. For example, if abrasion alert sleeve assemblies 14 take a longperiod of time to obtain after they are ordered, the relatively thinoutermost sleeve 34 depicted in FIG. 6 could serve as an “order now”indicator. When the contrasting indicator threads of the outermostsleeve 34 are noticeably revealed due to abrasion of the protectivethreads, a replacement abrasion alert sleeve assembly 14 could beordered. Since we are assuming in this scenario that it takes arelatively long time to manufacture and/or obtain a replacement abrasionalert sleeve assembly 14, the relatively thinner outermost sleeve 34results in early order placement and the relatively thicker intermediatesleeve 38 provides the main protection for the hydraulic or pneumaticlines until the replacement abrasion alert sleeve assembly 14 arrives.In this scenario, the innermost sleeve 36 may provide only backupprotection in case the abrasion alert sleeve assembly 14 cannot bereplaced before the intermediate sleeve 38 also fails.

Another advantage of abrasion alert sleeve assemblies comprisingmultiple multi-colored sleeves is that a user can estimate theapproximate life of a sleeve assembly by monitoring how long it takes towear through the individual layers of the abrasion alert sleeve assembly(i.e., by monitoring how long it takes for the indicator threads ofindividual layers to appear). This “monitoring” is easily done since theindicator threads may be different colored threads from one embeddedsleeve to the next. For example, a sleeve assembly could comprise fourtubular sleeves placed one inside the other. FIG. 5 depicts such asample of an abrasion alert sleeve assembly 12. Each of these fourembedded, abrasion alert sleeves 24, 26, 28, 30 could comprise indicatorthreads of a different color. If one were to monitor how long it takesto wear through the outermost sleeve 26, it would then be possible toestimate that the entire sleeve assembly 12 would need to be replaced inapproximately three times the number of days it took to wear through thefirst of the four embedded sleeves, assuming the sleeves are of the samethickness. Using that information, a purchaser of replacement sleeveassemblies 12 could better predict when it would be necessary to have areplacement sleeve assembly on hand since one could rapidly assess the“wear state” of the entire sleeve assembly by checking for how manycolors and what colors are visible on an installed sleeve assembly.

FIG. 7 is a fragmentary, isometric view of a piece of equipment 40(i.e., a forklift) having a plurality of hydraulic lines 42 operativelyconnected to a lifting mechanism 44 of the equipment. As depicted inFIG. 8, which is an enlarged, fragmentary view of the circled region ofFIG. 7, each hydraulic line 42 is protected by an abrasion alert sleeve10 or an abrasion alert sleeve assembly 12, 14 according to the presentinvention. As also shown in FIG. 8, the hydraulic lines move or shiftrelative to each other and to the equipment to which they are attachedas the pressure in the hydraulic lines fluctuates. In particular, FIG. 8depicts an active hydraulic line 46 next to an inactive hydraulic line48, and an arrow 50 represents movement of the active hydraulic line 46,46′ relative to the inactive hydraulic line 48. The active hydraulicline is shown in solid lines in a first position 46 relative to theinactive hydraulic line 48, and the active hydraulic line is shown inphantom in a second position 46′ relative to the inactive hydraulic line48.

FIG. 9 is similar to FIG. 8 and again depicts an active hydraulic line46, 46′ adjacent to an inactive hydraulic line 48. The active hydraulicline is moving laterally (i.e., side-to-side) under the influence ofpressure fluctuations. In particular, the active hydraulic line isdepicted in solid lines in a first position 46 relative to the inactivehydraulic line 48, and the active hydraulic line is depicted in phantomin a second position 46′ relative to the inactive hydraulic line 48. Inthis figure, movement of the active hydraulic line relative to theinactive hydraulic line is represented by the arrows 52. As the activehydraulic line moves back and forth in the direction of the arrowsbetween the first position 46 (solid lines) and the second position 46′(phantom lines), the active hydraulic line comes into and out of“bumping” contact with the inactive hydraulic line 48. During thisbumping contact, the abrasion alert sleeves 10 surrounding the hydrauliclines provide protection for the hydraulic lines.

FIG. 10 is similar to FIGS. 8 and 9, but is a fragmentary, isometricview of two hydraulic lines 46, 48, each protected by an abrasion alertsleeve 10, in “rubbing” contact with each other. As depicted in FIG. 10,movement of the active hydraulic line 46 is represented by a two-headedarrow 54. FIG. 10 shows a mildly-abraded area 56 wherein the protectivethreads 16 (e.g., FIG. 4) have begun to wear. FIG. 10 also shows aheavily-abraded area 58, wherein more of the protective threads havefailed, thereby revealing even more of the contrasting indicator threads20 (e.g., FIG. 4) (represented schematically by the differentcross-hatching in this figure). Clearly, the abrasion alert sleeves andsleeve assemblies according to the present invention not only protectthe hydraulic lines from each other (as shown in FIG. 10), but alsoprotect the hydraulic lines from wear caused by rubbing against adjacentparts of the equipment or machinery with which the hydraulic lines 42are associated.

As alluded to above in the discussion of FIGS. 5 and 6, the presentinvention also comprises a method of controlling inventory using thecontrasting colors of an abrasion alert sleeve 10 and/or the embeddedsleeves of an abrasion alert sleeve assembly 12, 14, wherein each sleeveof the sleeve assembly has indicator threads of a color that isdifferent from the indicator threads in the other embedded sleeves ofthe sleeve assembly. For example, an abrasion alert sleeve assembly maycomprise an outermost sleeve having blue indicator threads. When theblue indicator threads begin to appear, the person in charge of suppliescould order a new abrasion alert sleeve assembly and time the arrival ofthat new abrasion alert sleeve assembly to be close to the time when anabrasion alert sleeve assembly needs to be replaced. This outermostsleeve of the abrasion alert sleeve assembly thus serves as an “ordernow” indicator. The innermost abrasion alert sleeve of the abrasionalert sleeve assembly may include indicator threads that are, forexample, red. When the red indicator threads begin to be revealed, thiscould indicate that it is time to replace the abrasion alert sleeveassembly. The innermost abrasion alert sleeve would thus serve as a“replace now” indicator. This technique helps reduce excess inventorysince replacement abrasion alert sleeve assemblies are not ordered untiltheir need is imminent (i.e., when the blue threads begin to appear inthe above example).

Although a number of embodiments of this invention have been describedwith a certain degree of particularity, those skilled in this art couldmake numerous alterations to the disclosed embodiments without departingfrom the spirit or scope of this invention. For example, although twoabrasion alert sleeve assemblies are depicted in FIGS. 5 and 6, abrasionalert sleeve assemblies comprising more or fewer sleeves, or sleeveshaving different thicknesses or configurations from those depicted,could be made. An important aspect of the abrasion alert sleeveassemblies according to the present invention is that they comprise atleast one abrasion alert sleeve constructed from protective threads of abase color and indicator threads of a contrasting color. The abovedescription refers primarily to hydraulic lines, but the devicesdescribed herein are equally applicable to pneumatic or other hoseassemblies that experience potential abrasion during use. It should benoted that the abrasion alert sleeves and the abrasion alert sleeveassemblies described above are not designed to prevent rupture ofhydraulic or pneumatic lines. All dimensional references are only usedfor identification purposes to aide the reader's understanding of thepresent invention, and do not create limitations, particularly as to theposition, orientation, or use of the invention. It is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative only and not limiting.Changes in detail or structure may be made without departing from thespirit of the invention as defined in the appended claims.

1. An abrasion resistant device for the protection of a component thatwould otherwise be exposed to direct abrasion, the device comprising asingle-walled, tubular abrasion alert sleeve woven fromlongitudinally-extending, protective yarns of a base color interwovenwith laterally-extending, indicator yarns of a contrasting color,wherein said base color is different from said contrasting color, andwherein said protective yarns substantially conceal said indicator yarnsfrom view.
 2. An abrasion alert jacket comprising a single-walled,tubular structure having a longitudinal axis and constructed fromthreads having at least two contrasting colors to facilitate use of theabrasion alert jacket as a wear indicator, including a first pluralityof longitudinally-extending protective threads, said protective threadsbeing of a dominant color and being arranged substantially parallel tosaid longitudinal axis; and a second plurality of indicator threadsextending substantially perpendicularly to said first plurality oflongitudinally-extending protective threads, said indicator threadsbeing of an indicator color and being interwoven with said firstplurality of longitudinally-extending protective threads so as to besubstantially shielded by and hidden among said first plurality oflongitudinally-extending protective threads when said abrasion alertjacket is unworn, and wherein said indicator threads are adapted tobecome visible as said protective threads become worn.
 3. The abrasionalert jacket of claim 2, wherein said base color is black, and whereinsaid indicating color is selected from the group consisting of red,yellow, and orange.
 4. A multi-tube, sleeve assembly ofconcentrically-embedded sleeves for the protection of a criticalcomponent that would otherwise be directly exposed to abrasion, thesleeve assembly comprising an outermost, single-walled sleevecircumscribing a first interior region, said outermost sleeve beingconstructed from protective threads of a base color and indicatorthreads of a first contrasting color; and an innermost, single-walledsleeve circumscribing a second interior region, said innermost sleevebeing located inside said first interior region, said innermost sleevebeing constructed from protective threads of said base color andindicator threads of a second contrasting color, wherein said firstcontrasting color is different from said second contrasting color, andwherein the critical component resides within said second interiorregion.
 5. An abrasion alert sleeve assembly having a-tube-inside-a-tubeconstruction, the sleeve assembly comprising a first, single-walled,abrasion alert sleeve having a first longitudinal axis and constructedfrom threads of at least two contrasting colors to facilitate use ofsaid first abrasion alert sleeve as a first wear indicator, wherein saidthreads of said first abrasion alert sleeve include a first plurality oflongitudinally-extending protective threads, said first plurality ofprotective threads being of a first base color and being arrangedsubstantially parallel to said first longitudinal axis; and a secondplurality of indicator threads extending substantially perpendicularlyto said first plurality of protective threads, said second plurality ofindicator threads being of a first indicator color and being interwovenwith said first plurality of protective threads so as to besubstantially shielded by and hidden among said first plurality ofprotective threads when said first abrasion alert sleeve is unworn, andwherein said second plurality of indicator threads are adapted to becomemore clearly visible as said first plurality of protective threadsbecome worn; and a second, single-walled, abrasion alert sleeve having asecond longitudinal axis and constructed from threads having at leasttwo contrasting colors to facilitate use of said second abrasion alertsleeve as a second wear indicator, wherein said second abrasion alertsleeve is embedded within said first abrasion alert sleeve, and whereinsaid threads of said second abrasion alert sleeve include a thirdplurality of longitudinally-extending protective threads, said thirdplurality of protective threads being of a second base color and beingarranged substantially parallel to said second longitudinal axis; and afourth plurality of indicator threads extending substantiallyperpendicularly to said third plurality of protective threads, saidfourth plurality of indicator threads being of a second indicator colorand being interwoven with said third plurality of protective threads soas to be substantially shielded by and hidden among said third pluralityof protective threads when said second abrasion alert sleeve is unworn,and wherein said fourth plurality of indicator threads are adapted tobecome more clearly visible as said third plurality of protectivethreads become worn.
 6. The multi-walled, abrasion resistant sleeveassembly of claim 5, wherein said first base color is the same as saidsecond base color.
 7. A multi-walled, abrasion resistant sleeve assemblyconstructed from a plurality of embedded, single-walled, abrasion alertsleeves including an outermost, single-walled sleeve woven from threadsof at least two contrasting colors; and an innermost, single-walledsleeve woven from threads of a single color.
 8. The multi-walled,abrasion resistant sleeve assembly of claim 7 further comprising atleast one intermediate sleeve woven from threads of at least twocontrasting colors.
 9. The multi-walled, abrasion resistant sleeveassembly of claim 8, wherein said outermost sleeve is thinner than bothsaid innermost sleeve and said at least one intermediate sleeve, whereinsaid innermost sleeve is thicker than said outermost sleeve, and whereinsaid at least one intermediate sleeve is thicker than both saidoutermost sleeve and said at least one intermediate sleeve.
 10. Themulti-walled, abrasion resistant sleeve assembly of claim 8, whereinsaid outermost, single-walled sleeve; said innermost, single-walledsleeve; and said at least one intermediate sleeve are each ofsubstantially the same thickness.
 11. The multi-walled, abrasionresistant sleeve assembly of claim 8, wherein each of said outermost,single-walled sleeve; said innermost, single-walled sleeve; and said atleast one intermediate sleeve has a thickness that is different from thethickness of each of the other sleeves.
 12. The multi-walled, abrasionresistant sleeve assembly of claim 7 further comprising a firstintermediate sleeve woven from threads of at least two contrastingcolors and embedded between said outermost sleeve and said innermostsleeve; and a second intermediate sleeve woven from threads of at leasttwo contrasting colors and embedded between said first intermediatesleeve and said innermost sleeve.
 13. The multi-walled, abrasionresistant sleeve assembly of claim 7 further comprising a pull threadwithin said innermost abrasion alert sleeve.
 14. A method of protectinga critical component in an abusive environment using single-walled,multi-colored, abrasion alert sleeves, the method comprising the stepsof (a) installing a first abrasion alert sleeve over the criticalcomponent, said first abrasion alert sleeve comprising a first pluralityof protective threads of a first base color and a first plurality ofindicator threads of a first warning color, wherein said first pluralityof protective threads are woven with said first plurality of indicatorthreads so as to substantially hide said first plurality of indicatorthreads; (b) monitoring said first abrasion alert sleeve for theappearance of said first warning color; and (c) removing said firstabrasion alert sleeve and installing a replacement abrasion alert sleeveupon the appearance of a substantial amount of said first warning color.15. The method of claim 14, wherein said first base color is black andsaid first warning color is yellow, and wherein said critical componentin selected from the group consisting of hydraulic lines, pneumaticlines, and electrical leads.
 16. A method of protecting a criticalcomponent in an abusive environment using an abrasion alert sleeveassembly comprising a plurality of abrasion alert sleeves, the methodcomprising the steps of (a) installing a first abrasion alert sleeveassembly over the critical component, the first abrasion alert sleeveassembly comprising (1) an outermost, single-walled abrasion alertsleeve, said outermost abrasion alert sleeve comprising a firstplurality of protective threads of a first base color and a secondplurality of indicator threads of a warning color, wherein said firstplurality of protective threads are woven with said second plurality ofindicator threads so as to substantially hide said warning color; and(2) an innermost, single-walled abrasion alert sleeve, said innermostabrasion alert sleeve comprising a third plurality of threads of asecond base color; (b) monitoring said first abrasion alert sleeveassembly for the appearance of said warning color; and (c) removing andreplacing said outermost abrasion alert sleeve upon the appearance of asubstantial amount of said warning color.
 17. A method of protecting acritical component in an abusive environment using an abrasion alertsleeve assembly comprising a plurality of multi-colored, abrasion alertsleeves, the method comprising the steps of (a) installing a firstabrasion alert sleeve assembly over the critical component, the firstabrasion alert sleeve assembly comprising (1) an outermost,single-walled abrasion alert sleeve, said outermost abrasion alertsleeve comprising a first plurality of protective threads of a firstbase color and a first plurality of indicator threads of a first warningcolor, wherein said first plurality of protective threads are woven withsaid first plurality of indicator threads so as to substantially hidesaid first plurality of indicator threads; and (2) an innermost,single-walled abrasion alert sleeve, said innermost abrasion alertsleeve comprising a second plurality of protective threads of a secondbase color and a second plurality of indicator threads of a secondwarning color, wherein said second plurality of protective threads arewoven with said second plurality of indicator threads so as tosubstantially hide said second plurality of indicator threads; (b)monitoring said first abrasion alert sleeve assembly for the appearanceof said first warning color; (c) ordering a replacement sleeve assemblyupon the appearance of a substantial amount of said first warning color;(d) monitoring said first abrasion alert sleeve assembly for theappearance of said second warning color; and (e) removing said firstsleeve assembly and installing said replacement sleeve assembly upon theappearance of a substantial amount of said second warning color.
 18. Amethod of controlling inventory of abrasion resistant sleeve assembliesand ensuring timely replacement of worn abrasion resistant sleeveassemblies, the method comprising the steps of (a) installing anabrasion resistant sleeve assembly, said abrasion resistant sleeveassembly comprising embedded abrasion alert sleeves, including (1) anoutermost, order-now, abrasion alert sleeve, said outermost abrasionalert sleeve comprising a first plurality of protective threads of afirst base color and a first plurality of indicator threads of a firstwarning color, wherein said first plurality of protective threads arewoven with said first plurality of indicator threads so as tosubstantially hide said first plurality of indicator threads; (2) aninnermost, replace-now, abrasion alert sleeve, said innermost abrasionalert sleeve comprising a second plurality of protective threads of asecond base color and a second plurality of indicator threads of asecond warning color, wherein said second plurality of protectivethreads are woven with said second plurality of indicator threads so asto substantially hide said second plurality of indicator threads; (b)monitoring said abrasion resistant sleeve assembly during use forevidence of wear manifested as abraded and broken protective threadsthereby revealing said warning threads; (c) ordering a new abrasionresistant sleeve assembly upon the appearance of said first warningcolor; and (d) replacing said abrasion resistant sleeve assembly uponthe appearance of said second warning color.
 19. The method of claim 18,where step (a) further comprises adjusting the thickness of the abrasionalert sleeves comprising the abrasion resistant sleeve assembly toadjust the protection afforded by the abrasion resistant sleeveassembly.
 20. A method of establishing service intervals for abrasionalert sleeve assemblies being used to protect a critical component, themethod comprising the steps of (a) installing a first abrasion alertsleeve assembly over the critical component, the first abrasion alertsleeve assembly comprising a plurality of single-walled abrasion alertsleeves of approximately the same thickness, including (1) an outermost,single-walled abrasion alert sleeve, said outermost abrasion alertsleeve comprising a first plurality of protective threads of a firstbase color and a first plurality of indicator threads of a first warningcolor, wherein said first plurality of protective threads are woven withsaid first plurality of indicator threads so as to substantially hidesaid first plurality of indicator threads; (2) a first intermediate,single-walled abrasion alert sleeve, said first intermediate abrasionalert sleeve comprising a second plurality of protective threads of asecond base color and a second plurality of indicator threads of asecond warning color, wherein said second plurality of protectivethreads are woven with said second plurality of indicator threads so asto substantially hide said second plurality of indicator threads; (3) asecond intermediate, single-walled abrasion alert sleeve, said secondintermediate abrasion alert sleeve comprising a third plurality ofprotective threads of a third base color and a third plurality ofindicator threads of a third warning color, wherein said third pluralityof protective threads are woven with said third plurality of indicatorthreads so as to substantially hide said third plurality of indicatorthreads; and (4) an innermost, single-walled abrasion alert sleeve, saidinnermost abrasion alert sleeve comprising a fourth plurality ofprotective threads of a fourth base color and a fourth plurality ofindicator threads of a fourth warning color, wherein said fourthplurality of protective threads are woven with said fourth plurality ofindicator threads so as to substantially hide said fourth plurality ofindicator threads; (b) assessing a wear state of said first abrasionalert sleeve assembly by monitoring said first abrasion alert sleeveassembly for the appearance of at least one of said first warning color,said second warning color, said third warning color, and said fourthwarning color; (c) estimating a life expectancy for said first abrasionalert sleeve assembly by monitoring how long it takes for said firstwarning color to initially appear; (d) adjusting said estimated lifeexpectancy based upon how long it takes for said second and thirdwarning colors to initially appear; (e) ordering a replacement sleeveassembly based upon said estimated life expectancy; and (f) installingsaid replacement sleeve assembly upon the initial appearance of saidfourth warning color.